Metabolic and molecular signatures of improved growth in Atlantic salmon (Salmo salar) fed surplus levels of methionine, folic acid, vitamin B6 and B12 throughout smoltification.

• Main Authors: Adam, Anne-Catrin, Saito, Takaya, Espe, Marit, Whatmore, Paul, M.O. Fernandes, Jorge, Vikeså, Vibeke, Skjærven, Kaja Helvik
• Format: Text
• Language: unknown
• Published: figshare 2021
• Subjects: 70204 Animal Nutrition; FOS Animal and dairy science; 70401 Aquaculture; FOS Agriculture, forestry and fisheries; 70202 Animal Growth and Development; 60102 Bioinformatics; FOS Computer and information sciences; 60405 Gene Expression incl. Microarray and other genome-wide approaches; FOS Biological sciences; Molecular Biology; 60104 Cell Metabolism; Atlantic salmon; Salmo salar
• Online Access: https://dx.doi.org/10.6084/m9.figshare.14484489; https://figshare.com/articles/journal_contribution/Metabolic_and_molecular_signatures_of_improved_growth_in_Atlantic_salmon_Salmo_salar_fed_surplus_levels_of_methionine_folic_acid_vitamin_B6_and_B12_throughout_smoltification_/14484489

A moderate surplus of the 1C nutrients methionine, folic acid, vitamin B6 and B12 above dietary recommendations for Atlantic salmon has shown to improve growth and reduce hepatosomatic index in the on-growing salt water period when fed throughout smoltification. Metabolic properties and molecular mechanisms determining the improved growth are unexplored. Here, we investigate metabolic and transcriptional signatures in skeletal muscle taken before and after smoltification to acquire deeper insight into pathways and possible nutrient-gene-interactions. A control feed (Ctrl) or 1C nutrient surplus feed (1C+) were fed to Atlantic salmon six weeks prior to smoltification until three months after salt water transfer. Both metabolic and gene expression signatures revealed significant 1C nutrient-dependent changes already at pre-smolt, but differences intensified when analysing post-smolt muscle. Transcriptional differences revealed a lower expression of genes related to translation, growth, and amino acid metabolization in post-smolt muscle when fed additional 1C nutrients. The 1C+ group showed less free amino acid and putrescine levels, and higher methionine and glutathione (GSH) amounts in muscle. For Ctrl muscle, the overall metabolic profile suggests a lower amino acid utilization for protein synthesis, and increased methionine metabolization in polyamine and redox homeostasis, whereas transcription changes are indicative of compensatory growth regulation at local tissue level. These findings point to fine-tuned nutrient-gene-interactions fundamental for improved growth capacity through better amino acid utilization for protein accretion when salmon was fed additional 1C nutrients throughout smoltification. It also highlights potential nutritional programming strategies on improved post-smolt growth through 1C+ supplementation before and throughout smoltification.